This invention relates to a process for the production of a hydrated protein granule from a vegetable protein isolate which is suitable for use as an extender for meat products or as an ingredient in meat analogs.
Vegetable protein products including soy flour, soy concentrates and soy isolates have become widely used and accepted food ingredients. Among the vegetable protein products which have been the most widely accepted are the textured vegetable protein materials which have gained wide acceptance as a meat extender. The extended meat products are comparable in nutrition and quality to the natural meat products.
A variety of textured vegetable protein materials and processes for the production have been proposed. Generally recognized as one of the first processes for texturization of protein was that described in U.S. Pat. No. 2,682,466. Edible protein filaments were produced by a spinning process similar to that for the spinning of textiles. The starting material for this texturization process was a protein isolate, which has the bulk of oil and carbohydrates removed to achieve a protein content of 90-95% by weight on a dry basis.
Although numerous texturization techniques have been proposed for materials of lower protein content such as soybean meal, soy flour or concentrates, the most widely used and commercially successful technique for the texturization of vegetable protein material is the extrusion process described in U.S. Pat. No. 3,940,495. This process produces an expanded, meat simulating product which is capable of rehydration with water and upon rehydration is highly suitable as a meat extender. This type of extender was approved for use for the School Lunch Program by the U.S. Department of Agriculture, Food and Nutrition Service (FNS Notice 219) and since then has found wide usage in this program as well as by meat processors for the production of extended meat.
Other texturization processes too numerous to categorize have also been proposed following development of the extrusion process. These processes including the extrusion process, employ lower protein content vegetable protein materials as well as vegetable protein isolates. Some of these processes describe variations in the extrusion process described above in U.S. Pat. No. 3,940,495 for achieving differences in density or functionality of the textured product as well as an improvement or modification of the flavor or texture of the resultant product. Other processes have been directed to the production of non-expanded textured products, for example, an agglomerated protein material as described in U.S. Pat. No. 4,045,590 or an unpuffed proteinaceous extrudate as described in U.S. Pat. No. 3,498,794 and 3,968,268.
More recently U.S. Pat. No. 4,276,319 describes an extruded, dried and granulated protein gel suitable as a meat extruder which is prepared from a vegetable protein isolate.
A simple and effective procedure for the production of a composite protein material, consisting of meat and a vegetable protein isolate is described in European Pat. Publication No. 0352062 published Jan. 24, 1990 in which frozen meat is mixed with a vegetable protein isolate, and water and mixed under conditions of shear to form a composite product that blends readily with meat. This procedure has the advantage of simplicity, does not require expensive equipment and can therefore be readily performed by a food manufacturer at minimal expense.
In spite of the commercially developed nature of the vegetable protein industry, a continuing need exists for specific types of meat extenders exhibiting specific functional properties for various food uses.
It is also an object to provide for the production of a hydrated protein material from a vegetable protein isolate which exhibits desirable functional characteristics and blends well with ground meat to provide a mixture comparable to the natural meat.
It is also an object to provide for the production of a granule which is suitable as an ingredient in meat analogs.
It is a further object to provide a process for the production of the above material which is convenient and reliable to practice on a commercial basis.